Add Clang static analyzer to Clang toolchain defs in GN

base/logging.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_LOGGING_H_
 #define BASE_LOGGING_H_
 
 #include <stddef.h>
 
 #include <cassert>
@@ skipping 707 matching lines @@
   LAZY_STREAM(LOG_STREAM(DCHECK), false)                                \
   << "Check failed: " #condition ". "
 
 #define DPCHECK(condition)                                              \
   __analysis_assume(!!(condition)),                                     \
   LAZY_STREAM(PLOG_STREAM(DCHECK), false)                               \
   << "Check failed: " #condition ". "
 
 #else  // _PREFAST_
 
-#if defined(__clang_analyzer__)
+#if __has_feature(attribute_analyzer_noreturn)
+// Alternative DCHECK implementation for Clang static analysis.
 
-// Stops the analyzer from proceeding along the current codepath.
-void AnalyzerNoReturn() __attribute__((analyzer_noreturn)) {}
+// Prevents the analyzer from proceeding along the current codepath.
+// Function is short-circuit evaluated when a DCHECK condition fails.
+constexpr bool AnalyzerNoReturn() __attribute__((analyzer_noreturn)) {
+  return false;
+}
 
-#define DCHECK(condition)                                                   \
-  LAZY_STREAM(                                                              \
-      LOG_STREAM(DCHECK),                                                   \
-      DCHECK_IS_ON() ? (logging::AnalyzerNoReturn(), !(condition)) : false) \
+#define DCHECK(condition)                                                     \
+  LAZY_STREAM(                                                                \
+      LOG_STREAM(DCHECK),                                                     \
+      DCHECK_IS_ON() ? !((condition) || logging::AnalyzerNoReturn()) : false) \
       << "Check failed: " #condition ". "
 
-#define DPCHECK(condition)                                                  \
-  LAZY_STREAM(                                                              \
-      PLOG_STREAM(DCHECK),                                                  \
-      DCHECK_IS_ON() ? (logging::AnalyzerNoReturn(), !(condition)) : false) \
+#define DPCHECK(condition)                                                    \
+  LAZY_STREAM(                                                                \
+      PLOG_STREAM(DCHECK),                                                    \
+      DCHECK_IS_ON() ? !((condition) || logging::AnalyzerNoReturn()) : false) \
       << "Check failed: " #condition ". "
 
-#else  // __clang_analyzer__
+#else  // attribute_analyzer_noreturn
 
 #define DCHECK(condition)                                           \
   LAZY_STREAM(LOG_STREAM(DCHECK),                                   \
               DCHECK_IS_ON() ? !(condition) : false)                \
       << "Check failed: " #condition ". "
 
 #define DPCHECK(condition)                                          \
   LAZY_STREAM(PLOG_STREAM(DCHECK),                                  \
               DCHECK_IS_ON() ? !(condition) : false)                \
       << "Check failed: " #condition ". "
 
-#endif  // __clang_analyzer__
+#endif  // attribute_analyzer_noreturn
 
 #define DCHECK_INTERNAL_TEST(condition) \
   (DCHECK_IS_ON() ? !DCHECK_INTERNAL_ASSUME(condition) : false)
 
 
 #endif  // _PREFAST_
 
 // Helper macro for binary operators.
 // Don't use this macro directly in your code, use DCHECK_EQ et al below.
 // The 'switch' is used to prevent the 'else' from being ambiguous when the
@@ skipping 274 matching lines @@
 #elif NOTIMPLEMENTED_POLICY == 5
 #define NOTIMPLEMENTED() do {\
   static bool logged_once = false;\
   LOG_IF(ERROR, !logged_once) << NOTIMPLEMENTED_MSG;\
   logged_once = true;\
 } while(0);\
 EAT_STREAM_PARAMETERS
 #endif
 
 #endif  // BASE_LOGGING_H_